A scheme implementation of the infamous leftpad.js

leftpad.scm

(define (leftpad s l c)
	(if (number? s)
		(set! s (number->string s))
	)
	(if (number? c)
		(set! c (number->string c))   
	)
	(define (_leftpad _s _l _c)
		(if (<= _l 0) 
			_s
			(_leftpad (string-append _c _s) (- _l 1) _c)
		)
	)
	(_leftpad s (- l (string-length s)) c)
)

; https://repl.it/BzZZ/2
; (leftpad "foo" 5 " ")
; => "  foo"
; (leftpad "foobar" 6 " ")
; => "foobar"
; (leftpad 1 2 0)
; => "01"